Use memory compiler in compiler_helper.dart.

pkg/compiler/lib/src/js_backend/backend.dart

Index: pkg/compiler/lib/src/js_backend/backend.dart
diff --git a/pkg/compiler/lib/src/js_backend/backend.dart b/pkg/compiler/lib/src/js_backend/backend.dart
index e0311003aa1ea7cc2d8f6b729899b67a1b3e0e45..01298043d6a8cfd69260994804e6c9fbc810412d 100644
--- a/pkg/compiler/lib/src/js_backend/backend.dart
+++ b/pkg/compiler/lib/src/js_backend/backend.dart
@@ -1503,14 +1503,6 @@ class JavaScriptBackend extends Backend {
    */
   String assembleCode(Element element) {

[sigurdm, 2015/09/10 06:37:51]

Not from this cl - but `assembleCode` seems to be a bad name. What about
`generatedCode`?

[Johnni Winther, 2015/09/11 10:42:06]

Changed to 'getGeneratedCode' to indicate the passive behavior.

     assert(invariant(element, element.isDeclaration));
-    var code = generatedCode[element];
-    if (namer is jsAst.TokenFinalizer) {
-      jsAst.TokenCounter counter = new jsAst.TokenCounter();
-      counter.countTokens(code);
-      // Avoid a warning.
-      var finalizer = namer;
-      finalizer.finalizeTokens();
-    }
     return jsAst.prettyPrint(generatedCode[element], compiler).getText();
   }